Autistic Children Don't Benefit From Special Diets And Supplements, Study Shows

No shortage of quack therapies, particularly downright horrifying and dangerous ones, for “treating” autistic* children. An estimated one in 68 children have been diagnosed with an autism spectrum disorder, according to the Centers for Disease Control and Prevention, but the rash of misinformation that exists about the developmental disability, the paucity of evidence-based treatments that are accessible to all families and the overall lack of support in many communities means that too many parents will turn in desperation to whatever “therapy” they haven’t tried yet.

Among the most popular treatment regimens parents will try are a variety of nutritional interventions, whether it’s eliminating gluten and casein from their child’s diet or giving them supplements. Fortunately, most of these interventions carry little risk for harm, but do they offer much benefit, either? A new study in Pediatrics assessed the current research on these types of nutritional interventions and turned up with…not much.

Of the 19 randomized controlled trials the authors identified from the peer-reviewed research literature, only four of them had a low risk of bias, and five had a high risk of bias. The trials together included a total of 732 children and investigated the benefits of supplements, variations of the gluten-free and/or casein-free diet and other dietary treatments. The interventions lasted from a week to two years, depending on the intervention and on trial.

Assessing the benefits of gluten-free, casein-free diets was difficult because the studies differed so much in how the trial was designed and what outcomes the researchers were looking at. Although parents reported improvements with challenging behaviors and with communication with their children while using a gluten/casein-free diet in a few studies, the data told another story. Or, rather, the data told no story at all.

Brexton Busch, son of Kyle Busch, driver of the #18 Pedigree Toyota, stands in a car before the NASCAR Sprint Cup Series AAA 400 Drive for Autism at Dover International Speedway on May 15, 2016 in Dover, Delaware. (Photo by Jared C. Tilton/Getty Images)

The studies in which parents reported improvements did not show any lasting improvements based on objective measures or teacher reports. One study on these diets that showed significant parent-reported and objective improvement, using tests for communication, cognitive, motor, verbal and social skills, was rated as having a high risk of bias. Another only showed improvements at 12 months but not 24 months.

The trials basically did not yield enough evidence to draw any conclusions about the benefits of eliminating these proteins from children's diets. Similarly, no changes occurred in autistic children's behavior or in their gastrointestinal symptoms when they consumed a food containing gluten or casein after being on one of these diets.

Investigations into the use of supplements did not turn up much more. Omega-3 fatty acid supplements had no effect on improving challenging behaviors or any other areas, such as communication, language and adaptive behavior, though the supplements also appeared to have few risks, too. In a study of DHA supplements, parents reported seeing better social skills among children in the placebo group, but teachers reported better communication in the treatment group.

A reduction in the severity of symptoms did appear to occur with methyl B12 and levocarnitine, but the strength of the evidence wasn't sufficient to determine clear benefits. Likewise, the two trials that looked at digestive enzyme supplements, Peptizyde and Neo-Digestin, did not offer enough evidence to conclude that either had a profound effect on improving symptoms or difficulties.

The only real good news in this systematic review is that harms from these interventions seemed few and far between, though even that cannot be said with certainty.

“Despite their widespread reported use, little evidence supports the effectiveness of nutritional supplements or the gluten-free, casein-free diet for improving ASD symptoms,” wrote Nila Sathe and her colleagues at Vanderbilt University Medical Center in Nashville, Tennessee. “Harms reported in studies generally considered mild, but the long-term effects of these therapies are not well understood.”

Further, if parents are forgoing evidence-based therapies that address their child’s specific needs or support they can access locally, then the harm becomes greater. Worse, if they turn to many of the ideas promoted in the dark corners of the internet for autism, they may be trying something that’s not simply harmful but downright cruel, perhaps potentially fatal.

The authors noted that their findings matched up with what previous research reviews have found in assessing the evidence base, but they also acknowledged that many families continue to use supplement or nutritional approaches. Sometimes these diets line up with the parents’ personal views, or they want to feel they are doing something that has fewer perceived side effects.

“These findings continue to highlight the need for shared decision-making among provider and families,” the authors write, “including understanding of family motivations for using specific therapies and discussion of balancing potential benefits with potential risks and resource and time cost to families.”